Grid



March 26, 1940. DERQHE 2,195,079

GRID

Filed Sept. 14, 1938 INVENTOR.

RA YMOND DEROCHE ATTORNEY.

Patented Mar.26,1940' it l 1 5 079 P umrEov STATES-PA T OFFICE GRIDRaymond Deroche, Paris, France, assignor t Compagnie Generals DeTelegraphic Sans Fil, a corporation of France" Applicationseptember 14,1938, Serial No. 229,830 In France September 29, 1937 L 3 Claims.(am-27.5)

This invention relates to grids for electron disgrid. A straight linenormal to the cathode can charge devices or tubes. I be drawn in anyradial direction through the In tubes containing a plurality of gridssuch as axis of the cathode and the wires 6 and l of the tetrodes orpentodes, the screen grid which is two grids. The screen grid is thusshadowed interposed between the anode or plate and the electronically bythe control grid. If a larger 5' i control grid andv which is operatedat a positive number of turnsis desired on the control grid potential,absorbs primary electrons from the than on the screen grid, for example,one or'more cathode and consumes considerable current. The Wires 8 maybe wound onthe control grid side current taken by the screen grid isproportional, rods interleaved or between the turns 7 to give v 10 tothe total surface or area of the Wires'of this the desired number ofwires on the control grid. 10

grid .presented to or viewed from the cathode. The pitch of the twogrids and the number of l The energy which is thus dissipated by thescreen turns of wires of the control grid may be chosen grid provesrather troublesome, especially in in accordance with the characteristicof the tube power tubes and causes difiiculties in the conto besecured."- With thepitch and number of struction of the tubes. p turnsvariable design for given electrical charac- 15 It is feasible todiminish the current consumpteristics is. easy in manufacture. Thearrangetion and energy dissipation of grids by making ment will be founduseful for no matter what thegrids of helical windings of identicalpitch form of grid and regardless of the particular and mounting thegrids in such a Way that the function to be played by the differentgrids the wires or turns thereof as well as their supporting inventionmaybe applied to tubes with two or. 20

7 side rods come to cover one another or are placed more grids.

in registering relation. The screen grid, for ex- I claim: ample, may bedisposed so as to be electronically 1. An electron discharge devicecomprising a shadowed or sheltered by the turns of the control cathodeand anode, two helically wound grids of grid. 7 different diametersconcentrically about said cath- 2 However, to align the turns of .twogrids, the ode, the wire of one grid being of the same pitch turns mustbe wound with the same pitch. With and in radial alignment at all pointswith one wire wound grids of conventional construction wireon the othergrid, a second'wire wound on it. then becomes impossible to provide twoconsaid other grid, its turns being disposed between centric and alignedgrids with difierent turns per the turns of said one wire. 30 inch. ov2. An electron discharge device comprising a The arrangement heredisclosed overcomes the cathode; and anode, and two concentric wiredifiiculty of aligning two or more grids with difwound grids around thecathode and between'the ferent numbers of turns per inch. It consists incathode and, anode, one grid having plurality using for one of the gridshelicoidal spiraling of of helices on a common metal support and the 3several wires or threads of like pitch [on one other grid having onehelix, the pitch of: the helix pair of side rods. The turns of one wireis wound of the second mentioned grid being equal to the to cover orregister with the turns of the next pitch of the helices of the firstmentioned grid adjacent grid. Preferably, the supporting side and thehelix of the second mentioned grid being 40 rods of both these grids areinregistry. Accordin radial alignment with one of the helices of the 40ing to this invention two concentric grids of an first mentioned grid.electron, discharge device may haveregistering 3. An. electron dischargedevice comprising an helices, one of the grids having one ormoreaddienvelope, an anode, a cathode and at least two tional helicesdisposed between the turns of the concentric helically wound gridsaround the a ,g

one grid which'register with the other grid and cathode within saidanodeg one grid havinga wound in the surface of said turns of the onehelix with the same pitch and in radial aligngrid 4 ment at all pointswith awindingonthe other,

In the appended drawing is shown one tube grid and a second helix woundin the surface of embodying the invention-with an envelope I enthe helixof onegridand between the turns of closing a mount vvith'a cathode 2,anode 3, consaid one grid, said secondlhelix andthe turns of 50 trolgrid 4 and screen grid 5 supported as a unisaid one grid being supportedupon a common tary assembly on the press. The screen grid wire metalsupport;

- 6 is wound with the same pitch as and is positioned radially oppositethe wire I of the control j RAYMOND DEROCHE.

